This invention relates in general to the field of food preparation and more particularly to a method and apparatus for cooking animal meats for human consumption while removing much of the naturally occuring fat in the meat.
In recent years a great deal of attention and scientific and medical inquiry has been devoted to the study of the close link between the level of animal fats consumed in the typical human diet and the levels of fatty acids and cholesterol present in the blood. The motivation for these studies has been the concern that incidence of diseases of the blood vessels such as coronary heart disease and arteriosclerosis is associated with raised levels of fatty acids and cholesterol in the blood stream. As a consequence of these studies and concerns, medical scientists have been advising in both the scientific and popular press that humans reduce their consumption of dietary animal fat.
The usual suggestion for reducing the consumption of dietary animal fat is to stop eating meats high in such fats. While such a prohibition is usually directed to red animal meats, it is known that other meats including some derived from ocean animals contain high levels of cholesterol. Such a change in eating habits for a human population raised for millenia on animal meats has proved to be disconserting at best, and impossible to effectively practise at worst.
One reason that abstinence is suggested as the best policy for avoiding a high dietary intake of fats is that the typical methods used to cook meat result in much of the fat being retained in the meat. Despite the nuances found in all cook books, fundamentally most meats are cooked by one of two methods. The first method consists of plaing the surface of the meat in contact with a hot, thermally conducting, medium which is itself heated by an external source. Frying meat directly on a hot metal surface is a typical example of this method although sometimes water or oils are used as ancillary heat transfer aids. This method may result in the external surface of the meat becoming seared which further retards the ability of the fats to flow out of the meat. In addition, the usual cooking procedure involves turning the meat over several times so that all surfaces become seared. Even if no sealing of the meat surface to the flow of fat occurs, in this first general method the meat continues to sit and cook in its own fat. As a result, a substantial amount of the fat is reabsorbed and remains in the meat.
In the second general method of cooking meat, the meat surface is directly exposed to a radiant source of heat. Typically, the source emits in the infrared region of the electromagnetic spectrum although microwave radiation may also be used. The temperature may be very high as in broiling, or somewhat lower as in baking or roasting. With high temperatures, the meat surface is seared, thereby forming an effective barrier to the flow of fats from within the meat out through the surface. With lower temperatures and their longer cooking times, the meat surface is dried out and again acts as a barrier to the free flow of the internal fats out of the meat. The net result is that substantial amounts of the natural fats are retained in the meats.
Recently, a further concern has been raised about the manner in which most meats are cooked with the discovery that the use of high cooking heats results in the formation of a range of compounds which may possibly be mutagenic and/or carcinogenic. At the present time, most of these concerns center around the use of the very high surface temperatures found in direct frying and broiling. The compounds causing concern also seem to be created by the heat acting on at least some of the constituents of the fats. Whether such concerns will be raised about the use of lower heats is unknown at this time.
While not used frequently to cook meats, there are three other cooking methods which use water and steam. These methods differ substantially from the method of this invention. The first, pressure cooking, is accomplished by placing the food to be cooked in a completely sealed vessel containing a quantity of water. The food inside the vessel may or may not be initially placed in the water solution. As the vessel is heated, the water first turns to steam, and then the steam is heated to higher and higher temperatures. The high steam temperatures result in internal vapor pressures well in excess of atmospheric pressure. Temperatures significantly higher than 100 degrees Celcius are reached. The purpose of pressure cooking is to achieve these higher temperatures in order to reduce the cooking time.
A second method, poaching, consists of placing the item to be cooked in hot or boiling water. The cooking temperature may be that of boiling water or lower, but, once again, if this method is used with fatty meats, the meat sits and cooks in its own fats and is free to reabsorb those fats. In addition, the hot water in contact with the food acts to dissolve and remove other compounds including the flavor compounds from the food.
In the third method, steaming, food is placed above boiling water in a semi-closed vessel. No attempt is made to monitor the vapor pressure or the temperature around the food and usually as much steam is used as can be generated by the heating source and water volume. In addition, the vessel may be sufficiently closed so that there is a slight rise in internal pressure and a corresponding increase in temperature above 100 degrees Celcius.
In general, the above cited three methods are used to cook vegetables, although certain fish, such as salmon, are poached and some shellfish are steamed. However, the general cooking literature does not recognize or suggest that these methods be used to cook meats. The method of the present invention teaches how to take advantage of regulated hot steam to cook and defat meats in a way unanticipated and unrecognized by the prior cooking art.